The present invention relates to a choke valve control system which properly adjusts the opening of a carburetor choke valve of an internal combustion engine in response to the driving conditions of a vehicle.
Generally, a carburetor choke valve opening is controlled by a bimetallic spring which forces the valve to close during low temperatures and by an intake vacuum which acts upon the valve to open due to an eccentric shaft of the valve. Additionally, a diaphragm device is often used to reliably open the valve. The diaphragm device is linked with the choke valve shaft and actuated by the intake vacuum. However, in such a known choke valve control system, at a low temperature or at a low speed condition of the vehicle for example, the valve is sometimes excessively opened by the actuating force of the intake vacuum. Accordingly, in said known system, the choke valve opening is not always properly controlled in response to the driving conditions of the vehicle.